JPH0926596A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a parallax when a display is observed from diagonal by making it possible to form panels sufficiently thinner than the size of pixels without the need for forming substrates of a large thickness between respective liquid crystal cells as the respective independent driving of three layers of the liquid crystal cells is possible and there is no need for forming active elements respectively at these liquid crystal cells. SOLUTION: This liquid crystal display device consists of a substrate 7 formed with the plural active elements 4, 5, 6 for driving liquid crystals, the first, second and third liquid crystal cells 11, 12, 13 laminated in this order via interlayer films 15 on this substrate 7 and a substrate 10 laminated via a flattening film 26 on the third liquid crystal cell 13. The respective liquid crystal cells 11, 12, 13 consist of counter electrodes 17, 19, 25 formed on each of the respective liquid crystal cells, driving electrodes 14, 18, 20 connected to the active elements 4, 5, 6 and liquid crystal layers 1, 2, 3. At least one layers of the liquid crystal layers 1, 2, 3 are formed of high polymer dispersed liquid crystals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method for manufacturing the same, and more particularly, it is preferably applied to OA (office automation) equipment such as word processors and notebook computers, and various video equipment and game equipment. The present invention relates to a liquid crystal display device using a subtractive color mixing method and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, the application of liquid crystal display devices to word processors, laptop personal computers, portable television receivers called pocket televisions and the like has been rapidly developing. Conventionally, a TN method (twisted nematic) and an STN (super twisted nematic) method have been used for liquid crystal display devices. In this TN mode, a liquid crystal display element is arranged between a pair of polarizing plates, and the optical characteristics of the liquid crystal display element, that is, the optical rotation characteristic when no voltage is applied and the optical rotation elimination characteristic when a voltage is applied, are used for monochrome. (Black and white)
The display is performed.

For colorization, a color filter having a small size of, for example, red, blue, and green is provided for each display pixel, and the switching characteristics of the TN mode are used to perform multi-color display or full-color display by additive mixing. The method is generally used. There are two types of color display methods, additive color mixing and subtractive color mixing.The principle described here is called the additive color mixing method and is currently widely used in color liquid crystal display devices using active matrix driving or simple matrix driving. ing.

By the way, one of the problems of these liquid crystal display system is that the light transmittance is only a few percent. The light transmittance can be expressed as follows. Light transmittance = Aperture ratio of TFT array × Transmittance of liquid crystal × Transmittance of polarizing plate × Transmittance of color filter The values in the liquid crystal display currently used are generally the aperture ratio of the TFT array (60 to 70%), the liquid crystal. The transmittance (90 to 95%), the polarizing plate transmittance (40%), and the color filter transmittance (30%) are calculated, and the light transmittance is calculated to be 6.5 to 8%. Most of these are not being used effectively. Therefore, it is difficult to perform color display without using a backlight with high power consumption, and the low power consumption, which is an advantage of the liquid crystal display element, is lost.

On the other hand, when performing color display using the subtractive color mixture method, since the liquid crystal cell having a three-layer structure is used for color development, it is not necessary to use the above color filter. Therefore, in the above equation, the portion corresponding to the color filter transmittance is deleted, and in principle, it can be brighter than the additive color mixture method and is expected.

FIG. 17 shows an example of a liquid crystal display device using the subtractive color mixture method. The liquid crystal display device 90 includes a first liquid crystal cell 94 a, a second liquid crystal cell 95 a, a third liquid crystal cell 96 a, a flattening film 26, a black matrix 28, and a second substrate on the first substrate 7 with an interlayer film 15 interposed therebetween. 10 are stacked and configured. The first liquid crystal cell 94a includes the interlayer film 15
Liquid crystal driving element 91 and liquid crystal driving element 9 formed above
The drive electrode 84, the liquid crystal layer 94, and the counter electrode 85 connected to 1 are laminated in this order. Also, the second
The liquid crystal cell 95a is configured by laminating a substrate 97, a liquid crystal driving element 92 formed on the substrate 97, a driving electrode 86 connected to the liquid crystal driving element 92, a liquid crystal layer 95, and a counter electrode 87 in this order. ing. The third liquid crystal cell 96a includes a substrate 98, a liquid crystal driving element 93 formed on the substrate 98,
A drive electrode 88 connected to the liquid crystal drive element 93, a liquid crystal layer 96, and a counter electrode 89 are laminated in this order. In the liquid crystal display device 90 formed in this way, for example, a guest-host (GH) system is adopted as the liquid crystal material, and three layers of liquid crystal that emit cyan, magenta, and yellow are laminated, and multi-color or full-color It has already been proved that it is possible to display (Reference: Tatsuo Uchida, "Next Generation Liquid Crystal Display Technology" Industrial Research Council pl72).

However, in this system, three layers of liquid crystal cells are stacked, so that a glass substrate or the like is inserted between the liquid crystal layers, and the thickness thereof causes a color shift of three colors when the display is observed obliquely. The problem is that it occurs. In order to solve this, it is necessary to make the thickness of the substrate sufficiently smaller than the size of the pixel. For example, a method of stacking three layers of cells manufactured by using a plastic film substrate can be considered, but it is difficult to form an element such as a thin film transistor (TFT) on a plastic film having poor heat resistance due to process temperature restrictions. is there. Further, in the case of manufacturing a liquid crystal driving active element such as a TFT for each liquid crystal layer with such a three-layer structure, the number of steps of the liquid crystal cell is almost three times the current number, and the manufacturing cost and the yield are also increased. Very disadvantageous.

Therefore, Japanese Patent Laid-Open No. 6-337643 proposes a liquid crystal display panel 100 as shown in FIG. The liquid crystal display panel 100 includes a first substrate 10
A plurality of liquid crystal cells 101, 102, 103 are laminated on a plurality of liquid crystal driving elements 110 formed on the display panel 8. Each of the liquid crystal cells 101, 102 and 103 includes a drive electrode 105, 106 and 107 and a liquid crystal layer 11 respectively.
1, 112, and 113 respectively, and the counter electrode 104 formed only on the second substrate 109 is configured as a common electrode. That is, each liquid crystal layer 111, 11
The space between 2 and 113 is partitioned only by the drive electrodes 106 and 107. In the case of such a structure, since no glass substrate or the like is inserted between the liquid crystal cells 101, 102, 103, it is possible to prevent the occurrence of parallax due to the thickness thereof. However, in the liquid crystal display panel 100, since the liquid crystal layers 111, 112, and 113 are connected in series, it is difficult to apply an electric field independently to each other.
It is necessary to introduce a complicated driving method such as setting the potentials of 6 and 107 by the liquid crystal driving element 110 connected to each of them and generating an electric field only in a portion corresponding to a necessary liquid crystal layer. Therefore, the driving voltage as a whole becomes high due to the necessity of controlling each liquid crystal driving element 110 independently, and a driving circuit capable of withstanding the voltage is required, which causes an increase in the manufacturing cost of the liquid crystal display device as a whole. Becomes

The present invention has been made in view of the above problems, and improves the utilization efficiency of light, reduces the power consumption of the liquid crystal display device, and prevents the color shift of the image display to enable full-color display. In addition, it is an object of the present invention to provide a liquid crystal display device and a method of manufacturing the same, which can reduce an increase in manufacturing cost.

[0010]

According to the present invention, a first substrate having a plurality of liquid crystal driving active elements formed thereon, and a first substrate laminated in this order on the first substrate with an interlayer film interposed therebetween are provided. The second and third liquid crystal cells, and the second substrate laminated on the third liquid crystal cell with a planarization film interposed therebetween.
The third liquid crystal cell includes a counter electrode formed for each liquid crystal cell, a liquid crystal layer, and a drive electrode connected to a liquid crystal driving active element on the first substrate. In the liquid crystal display device, the driving electrodes are electrically separated from each other by an insulating layer, and at least one of the liquid crystal layers constituting the first, second and third liquid crystal cells is formed of polymer dispersed liquid crystal. Provided.

From another point of view, according to the manufacturing method of the present invention, (i) a plurality of liquid crystal driving active elements are formed on the first substrate, and an interlayer film is formed on the entire surface of the liquid crystal driving active elements. And (ii) forming a first liquid crystal cell by laminating a drive electrode connected to the first active element for driving a liquid crystal, a liquid crystal layer, and a counter electrode on the interlayer film in this order, iii) A second liquid crystal cell is formed by stacking a drive electrode connected to a second liquid crystal drive active element through an insulating layer on the first liquid crystal cell, a liquid crystal layer, and a counter electrode in this order. And (iv) a drive electrode connected to a third liquid crystal drive active element via an insulating layer on the second liquid crystal cell, a liquid crystal layer, and a counter electrode are laminated in this order to form a third liquid crystal layer.
It is possible to provide a method for manufacturing a liquid crystal display device, which comprises forming a liquid crystal cell and laminating a second substrate on a third liquid crystal cell with a planarizing film interposed therebetween.

Further, according to another manufacturing method of the present invention,
(I) Forming a plurality of liquid crystal driving active elements on the first substrate,
An interlayer film is formed on the entire surface of the liquid crystal driving active element, and (II)
A counter electrode, a liquid crystal layer and a drive electrode are laminated in this order on a second substrate with a planarizing film interposed therebetween to form a third liquid crystal cell, and (II
I) a second liquid crystal cell is formed by laminating a counter electrode, a liquid crystal layer and a driving electrode in this order on the third liquid crystal cell with an insulating layer interposed therebetween, and (IV) forming an insulating layer on the second liquid crystal cell. Counter electrode through,
A liquid crystal layer and a drive electrode are laminated in this order to form a first liquid crystal cell, and (V) the obtained first substrate and second substrate are connected to each active element for driving liquid crystal and the drive electrode. There is provided a method for manufacturing a liquid crystal display device, which comprises laminating the liquid crystal display device.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The first substrate in the present invention is not particularly limited in the case of a reflection type liquid crystal display device, and a known opaque insulating substrate such as a silicon substrate or a translucent insulating substrate is used. A substrate such as glass, quartz, or plastic can be used, and a substrate provided with an undercoat film of silicon oxide, SiN, or the like can also be used. In the case of a transmissive liquid crystal display device, it is preferable to use a translucent insulating substrate.

A plurality of liquid crystal driving active elements are formed on the first substrate. As an active element for driving liquid crystal,
There is no particular limitation, and a non-linear resistance element such as a thin film transistor (TFT) or MIM (Metal Insulator Metal) element can be used. In the case of a reflective liquid crystal display device, a MOS transistor or the like may be used. Good. The materials, sizes, etc. of these elements can be appropriately adjusted according to the desired functions, sizes, etc. of the liquid crystal display device.

Further, the first, second and third liquid crystal cells are laminated in this order on the first substrate on which the liquid crystal driving active elements are formed, with an interlayer film interposed therebetween. An insulating layer is formed between each of the first, second and third liquid crystal cells and electrically isolated. Si as the material for the interlayer film
A single or a plurality of laminated films such as O ₂ and SiN have a film thickness of 0.1.
The thickness is preferably about 3 μm. The insulating layer is not particularly limited as long as it can reduce the capacitance between the liquid crystal cells, and it is preferable to use a material having a relative dielectric constant as small as possible. Specific examples thereof include transparent polymer materials such as methyl methacrylate, polyethylene terephthalate, polystyrene, polyvinyl chloride, and polyethylene, or materials that can be used as an insulating substrate. The film thickness at this time is, for example, 10
About 200 μm is preferred.

Each liquid crystal cell comprises a pair of drive electrodes and counter electrodes formed for each liquid crystal cell and a liquid crystal layer, and the drive electrodes are electrically insulated from the drive electrodes and counter electrodes of adjacent liquid crystal cells. Has been done. The drive electrodes forming each liquid crystal cell are formed on the interlayer film in the case of the first liquid crystal cell, on the insulating layer in the case of the second and third liquid crystal cells, and in the liquid crystal driving active element on the first substrate. InO is connected and formed.
A transparent conductive material such as ₃ , SnO ₂ , ITO (Indium Tin Oxide) or the like can be used in a film thickness of about 30 to 500 nm, more preferably about 50 to 200 nm. In the case of a reflection type liquid crystal display device, it is preferable to use a conductive material having a function of a reflection plate as the drive electrode forming the first liquid crystal cell. Specifically, aluminum, silver, platinum,
Nickel, chromium or the like can be used in a film thickness of about 10 nm to 1 μm, more preferably about 50 to 500 nm. In the reflective liquid crystal display device as well, a transparent conductive material can be used as the drive electrode forming the first liquid crystal cell, but in this case, it can be used as the above-described reflector besides the drive electrode. First possible conductive material
It is necessary to form it either between the substrate and the first liquid crystal cell, outside the first substrate, between the drive electrode in the first liquid crystal cell and the liquid crystal layer, or the like.

The counter electrode is orthogonal to the driving electrode and is arranged parallel to the driving electrode and the substrate surface. As the material of the counter electrode, it is preferable to form the above-mentioned transparent conductive material in the same film thickness.
The liquid crystal layers are different dyes, for example, azo-based, anthraquinone-based, diazo-based, azomethine-based, naphthoquinone-based or perylene-based dyes, more specifically magenta,
It is preferably configured to include a dichroic dye such as cyan and yellow. The liquid crystal cell at this time is 3 to 30 μm.
It is preferable to have an interval of about m. The liquid crystals used in each liquid crystal layer may be different or the same except that they contain different dyes. However, it is preferable that a polymer-dispersed liquid crystal using a guest-host liquid crystal is used in at least one layer, and preferably in all the layers. The polymer-dispersed liquid crystal is one in which the liquid crystal is present in a polymer matrix in the form of small droplets of about 0.1 to 20 μm, and the liquid crystal is 2 times as large as the polymer-dispersed liquid crystal.
It is preferably contained in an amount of about 0 to 80 w / w% (or v / v%). The liquid crystal is not particularly limited, and for example, a Schiff base type, an azo type, an azoxy type,
Benzoic acid ester type, biphenyl type, terphenyl type,
Examples thereof include nematic liquid crystals such as cyclohexycarboxylic acid ester-based, phenylcyclohexane-based, pyrimidine-based and dioxane-based or a mixture thereof, and ferroelectric liquid crystals such as phenylpyrimidine-based. Further, as the material for forming the polymer matrix, for example, acrylic, methacrylic, epoxy or UV-curable allyl resin, specifically, 2-ethylhexyl acrylate, urethane acrylate, butyl acrylate, vinyl alcohol,
Examples thereof include methyl methacrylate, and polymers obtained by polymerizing these oligomers.
Additives such as a photocuring initiator, a chiral agent, and a surface active agent may be optionally added to these liquid crystal layers. Further, as a method for orienting the dye contained in the liquid crystal layer,
For example, the temperature at which the liquid crystal material is isotropic (for example, 80 to 1).
While maintaining the temperature at about 20 ° C.), an electric field is applied so that the dichroic dye is oriented, and ultraviolet rays are irradiated while maintaining such an electric field to cure the material forming the polymer matrix. To be The electric field at this time is 10
It is preferable to apply the voltage for about 0 to 1000 kV / cm for 10 to 60 minutes.

In the liquid crystal display of the present invention,
When the polymer-dispersed liquid crystal is used, an alignment film is not particularly necessary, but an alignment film may be appropriately formed depending on the type and properties of the liquid crystal used, and further, optionally on the drive electrode or the counter electrode or A single film or a laminated film such as a protective film or an insulating film may be formed on the lower side. Examples of the alignment film, the protective film, or the insulating film include SiO ₂ , SiN, Al ₂ O ₃ , epoxy, silicone, polyimide, photoresist resin, and the like, which are deposited, sputtered, CVD, LPCVD,
Solution coating method, spinner coating method using a solution in which an organic substance is dissolved or a precursor solution thereof, dip coating method, screen printing method, roll coating method, etc., and under predetermined curing conditions (heating, light irradiation, etc.) It can be formed by a method of curing. The film thickness at that time is not particularly limited, and can be appropriately adjusted depending on the size of the liquid crystal display device, the thickness of the liquid crystal layer to be formed, the drive electrodes and the counter electrodes, and the like.

The counter electrodes forming the first, second and third liquid crystal cells are respectively connected to the liquid crystal driving active elements on the first substrate. The connection can be made by, for example, an interlayer film, an insulating layer, and a three-dimensional wiring penetrating each liquid crystal cell. Specifically, the counter electrode of the first liquid crystal cell is formed by three-dimensional wiring that penetrates the interlayer film formed on the liquid crystal driving active element, and the counter electrode of the second liquid crystal cell is formed on the liquid crystal driving active element. The counter electrode of the third liquid crystal cell is connected to the interlayer film, the first liquid crystal cell, the insulating layer, and the Two three-dimensional wirings penetrating the liquid crystal cell and the insulating layer are connected to the liquid crystal driving active elements on the first substrate, respectively. The three-dimensional wiring at this time is made of, for example, the same material as the drive electrode and the transparent electrode, Al,
It can be formed of a conductive material such as Ni, Ti, Ta, or Ag.

The above liquid crystal display device can be manufactured by the following method. First, in step (i), (a)
A plurality of active elements for driving liquid crystal are formed on the first substrate. A liquid crystal driving active element is formed by a known method, for example, in the case of a thin film transistor, hydrogenated amorphous silicon is formed as an active layer, a gate insulating film and a gate electrode are formed thereon, and a source / drain region is formed by ion implantation. It can be manufactured by forming. (B) A known method such as C
An interlayer film is formed by the VD method, the vapor deposition method, or the like. (C) On the active layer for driving the liquid crystal, which is the interlayer film, the first layer is formed in a later step.
It is preferable to form a contact hole for use in forming a three-dimensional wiring connecting the liquid crystal driving active element on the substrate and the driving electrode of each liquid crystal cell. The contact hole can be formed in a desired size by a known method such as photolithography and etching.

In step (ii), a first liquid crystal cell is formed on the interlayer film. (A) First, a material to be a drive electrode is laminated on the interlayer film by, for example, a sputtering method or an evaporation method, and is patterned into a desired shape by a photolithography and etching method to form a drive electrode. At this time, when the contact hole is formed in the previous step, the drive electrode is connected to the liquid crystal drive active element through the three-dimensional wiring made of the material to be the drive electrode buried in the contact hole. Become. (B) Further, it is preferable that at least two electrode pads are formed as a three-dimensional wiring connected to another active element for driving liquid crystal. This electrode pad may be formed of the same material as the driving electrode at the same time, or a known method,
For example, it may be formed after forming the drive electrode using another material by sputtering, electroless plating, or the like.
As the electroless plating method, for example, there is a method of forming a Ni film from a NiSO ₄ solution on Al, but it is not limited to Al and Ni, and Ti, Ta, Ag or the like may be used. (C) An insulating film, a protective film or the like may be optionally formed on the drive electrode, and then a liquid crystal layer is formed. The method for forming the liquid crystal layer is not particularly limited, and known methods such as liquid crystal layer separation, liquid crystal emulsion coating, and liquid crystal impregnation can be used. Specifically, a method in which a liquid crystal is dispersed in a water-soluble polymer, the polymer is applied onto a driving electrode by a bar coater or the like, and if necessary, the polymer is polymerized by heat, ultraviolet rays or an electron beam, and then dried. can give. (D) Further, a protective film or an insulating film is optionally formed on the obtained liquid crystal layer to form a counter electrode. The counter electrode can be formed similarly to the drive electrode. (E) In this step, the first liquid crystal cell is used to connect the liquid crystal driving element on the first substrate to the driving electrodes of the second and third liquid crystal cells, and not to connect to the counter electrode. It is preferable to form at least two electrode pads as the three-dimensional wiring that penetrates. The electrode pad is
After forming the counter electrode, the liquid crystal layer is etched by a known method such as wet etching, dry etching, or oxygen ashing using a material having high oxygen plasma resistance such as polysilane or disilanylene-π-electron polymer as a resist. , A through hole is formed, and a conductive material is embedded in the through hole. Alternatively, a through hole may be formed before forming the counter electrode, and the counter electrode material may be deposited in the through hole.

In the step (iii), a second liquid crystal cell is formed on the first liquid crystal cell via an insulating layer. (A) As described above, the insulating layer is preferably formed of a transparent polymer material, and these materials are dissolved in, for example, chloroform or the like and applied by a bar coater or the like to 50 to 200 ° C.
Preferably, it can be formed by drying at a temperature of around 100 ° C. for about 1 to 60 minutes. (B) A drive electrode is formed on this insulating layer in the same manner as in the method in step (ii). (C) At this time, it is preferable that at least two electrode pads are formed as a three-dimensional wiring used to connect the liquid crystal driving element on the first substrate and the driving electrodes of the second and third liquid crystal cells. . In this electrode pad, before forming the drive electrode, the insulating layer is etched by a known method such as wet etching, dry etching or oxygen ashing to form a through hole, and the drive electrode material is embedded in the through hole. Thus, the same material as that of the drive electrode can be formed at the same time, or the drive electrode can be formed and then another conductive material can be used. At least one of these electrode pads is connected to the drive electrode of the second liquid crystal cell, and is connected to the liquid crystal drive active element on the first substrate via the plurality of electrode pads formed previously. On the other hand, the other electrode pads are electrically insulated from the drive electrodes of the second liquid crystal cell. (D) An insulating film, a protective film, or the like may be optionally formed on the drive electrode, and then a liquid crystal layer is formed. The liquid crystal layer is formed as described above. (E) Further, a protective film or an insulating film is optionally formed on the obtained liquid crystal layer to form a counter electrode. The counter electrode is
It can be formed in the same manner as the drive electrode. (F) In this step, the liquid crystal driving element on the first substrate and the third
Used to connect to a driving electrode of a liquid crystal cell, first
Also, it is preferable to form an electrode pad penetrating the second liquid crystal cell. Similar to the method in step (ii), the second
It can be formed without being connected to the counter electrode of the liquid crystal cell.

In step (iv), the drive electrode and the liquid crystal layer are formed on the second liquid crystal cell via the insulating layer by the same method as in step (a) (iii). At this time, the process (ii
It is preferable to form an electrode pad as a three-dimensional wiring connected to the drive electrode similarly to i). As a result, the drive electrode is connected to the liquid crystal drive active element on the first substrate via the plurality of electrode pads previously formed. (B) Then,
The counter electrode may be formed in the same manner as in step (iii) to form a third liquid crystal cell, and a second substrate may be laminated on the third liquid crystal cell via a flattening film, or (b ′) separately. The counter electrode was formed on the second substrate via the planarization film, and the second electrode was obtained.
It may be formed by laminating the substrate on the liquid crystal layer of the third liquid crystal cell. At this time, a black matrix may be optionally formed between the second substrate and the flattening film by a known method. In addition, the flattening film at this time is made of epoxy resin, acrylic resin, polyimide resin, or the like.
It is preferable to form the film having a thickness of about 0.5 to 10 μm.

After the above steps, a desired wiring is provided to the counter electrode of each liquid crystal cell, and a liquid crystal driving active element is mounted on a mounting circuit to complete a liquid crystal display device. Further, in another manufacturing method of the present invention, in the step (I), a plurality of liquid crystal driving active elements are formed on the first substrate as in the above step (i), and the entire liquid crystal driving active element is formed. In addition, an interlayer film can be formed. At this time, it is preferable to form a contact hole as in the above step (i), and a conductive material is embedded in the contact hole to form a bump that can be used as a three-dimensional wiring connected to each liquid crystal driving active element. It is preferable.

In this manufacturing method, the substrate on the upper surface of the liquid crystal display device is formed by the reverse process of the above manufacturing method. That is, in the step (II), the third liquid crystal cell is formed on the second substrate via the flattening film. The flattening film is
It can be formed by a method similar to the above steps (iv) and (b '), and a counter electrode, a liquid crystal layer and a drive electrode are laminated in this order on this flattening film. The counter electrode, the liquid crystal layer, and the drive electrode can be formed by the same method as described above. Even in this case, a single layer or a laminated layer of the protective film and the insulating film may be optionally formed on the upper side or the lower side of the counter electrode and the drive electrode, or on one of them.

In step (III), a counter electrode, a liquid crystal layer and a drive electrode are laminated in this order on the drive electrode of the third liquid crystal cell with an insulating layer interposed therebetween to form a second liquid crystal cell. The insulating film, the counter electrode, the liquid crystal layer and the drive electrode in this step can all be formed by the same method as described above.
Further, in the step (IV), the counter electrode, the liquid crystal layer and the drive electrode are laminated in this order on the drive electrode of the second liquid crystal cell through an insulating layer to form a first liquid crystal cell. To do. In the case of a reflective liquid crystal display device, an insulating film having unevenness is further formed between the liquid crystal layer and the driving electrode so that unevenness can be formed on one surface of the driving electrode so as to form unevenness on the one surface of the driving electrode. Preferably. The unevenness on the surface of the insulating film can be formed by a known etching method or the like. At this time, the irregularities are preferably arranged in an irregular pattern so that the reflected light does not have wavelength characteristics due to diffraction or interference.

In the above steps (II), (III) and (IV), the steps (ii), (iii) and
Similar to (iv), it is preferable to form electrode pads as three-dimensional wiring. In step (V), the obtained first substrate and second substrate are laminated so that each liquid crystal driving active element and each driving electrode are connected. At this time, when the bumps corresponding to the respective liquid crystal driving active elements of the first substrate are formed in the previous step, the anisotropic conductive film is used for the bumps and the electrode pads formed in the previous step. Therefore, it is preferable to connect them. Accordingly, each liquid crystal driving active element can be connected to the drive electrodes forming the first, second and third liquid crystal cells via the electrode pads and the bumps. The anisotropic conductive film used at this time has, for example, a diameter of 3 to 10 μm.
It is possible to use a thermosetting resin such as an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a polyester resin, or a polyimide resin in which approximately spherical fine conductive particles of about m are mixed, and the temperature is about 100 to 200 ° C. By applying a pressure of about 10 to 50 g / pad at the temperature of 1, the electrode pad or the drive electrode and the bump can be electrically connected.

In the liquid crystal display device of the present invention,
When used as a transmissive liquid crystal display device, a backlight, a reflective film, or the like can be optionally disposed on the surface of the first substrate opposite to the liquid crystal cell. Hereinafter, specific examples of the liquid crystal display device and the manufacturing method thereof according to the present invention will be described. Embodiment 1 FIG. 1 shows one pixel of a transmissive liquid crystal display device of an active matrix drive using a subtractive color mixture method for color display in the present invention, and FIG. 2 shows vertical wiring of this device.

The liquid crystal display device 47 is constructed as follows. Liquid crystal driving TFTs 4, 5 and 6 such as thin film transistors corresponding to drive electrodes of each liquid crystal layer described later are formed on a first substrate 7 made of glass. In the first liquid crystal cell 11, the liquid crystal driving TFTs 4, 5,
Drive electrodes 14 formed on the interlayer film 15 coated on 6 and connected to the liquid crystal drive TFT 4 are formed,
The first liquid crystal layer 1 is formed on the drive electrodes 14. The protective film 41 and the SiO ₂ film 4 are formed on the first liquid crystal layer 1.
2 and the counter electrode 17 are formed.

In the second liquid crystal cell 12, a liquid crystal driving T is provided on the counter electrode 17 via the insulating layer 8 and the SiO ₂ film 43.
The drive electrode 18 connected to the FT 5 is formed, and the second liquid crystal layer 2 is formed on the drive electrode 18. A protective film 44, a SiO ₂ film 45 and a counter electrode 19 are formed on the second liquid crystal layer 2. In the third liquid crystal cell 13,
The drive electrode 20 connected to the liquid crystal drive TFT 6 via the insulating layer 9 and the SiO ₂ film 46 is formed on the counter electrode 19, and the third liquid crystal layer 3 is formed on the drive electrode 20. There is. A counter electrode 25 is formed on the third liquid crystal layer 3.

A transparent second substrate 10 is disposed on the counter electrode 25 with a flattening film 26 and a black matrix 28 interposed therebetween. First, second and third liquid crystal layers 1, 2, 3
Is formed by dispersing microcapsule guest-host type liquid crystal in a polymer matrix, and contains dichroic dyes of yellow, magenta and cyan, respectively.

Further, the liquid crystal cells 13, 12 of the first substrate 7,
A light guide plate 22 and a reflective film 23 are provided on the side opposite to 11, and the backlight light source 21 is used. The vertical wiring will be described in more detail with reference to FIG. Liquid crystal driving TFT formed on the first substrate 7.
The drive electrode 14 is directly connected to the switch 4. The liquid crystal driving TFT 5 has electrode pads 14a, 33a and 35a.
The drive electrode 18 is connected via. Further, the liquid crystal driving TFT 6 includes electrode pads 14b, 33b, 35.
The drive electrode 20 is connected via b, 34b, and 36b.

Although the structure of the liquid crystal driving TFTs 4, 5 and 6 is not shown in FIGS. 1 and 2, these liquid crystal driving TFTs 4, 5 and 6 have a gate electrode on the first substrate 7. Each is formed, an active layer is formed on it via a gate insulating film, and source / drain electrodes are connected to both ends of the active layer, respectively. The liquid crystal display device 47 is manufactured as follows.

First, as shown in FIG. 3, Corning #
Hydrogenated amorphous silicon (a-Si: H) is used as an active layer on a transparent first substrate 7 having an undercoat film made of silicon oxide on the surface of soda glass such as 7059 by a technique known as an active element. TFT4,
5 and 6 were produced. After that, an SiO ₂ film having a film thickness of about 500 nm is formed as an interlayer film 15 on the TFTs 4, 5, and 6. A contact hole is formed in a desired region of the interlayer film 15, and ITO having a film thickness of about 100 nm is formed on the entire surface of the interlayer film 15 including the contact hole by a sputtering method, and the TFT 4 is formed through the contact hole by a photolithography and etching process. The transparent drive electrode 14 connected to the TFTs 5 and 6 was formed, and the electrode pads 14a and 14b connected to the TFTs 5 and 6 were formed.

Next, a nematic liquid crystal ZLI-356 was prepared by adding 1 gram of TWEEN 20 (manufactured by ICI America) as a surfactant to 15 grams of a 12% aqueous solution of polyvinyl alcohol (PVA) having a polymerization degree of about 500.
1-000 (manufactured by Merck & Co.) in dichroic dye (any one of cyan, magenta and yellow. For example, yellow G2
32 (manufactured by Japan Photosensitive Dye Laboratories) was added, and 9 g of the mixture was mixed and stirred at 5000 rpm for about 10 minutes to emulsify. Next, copolymer latex 4 of methyl methacrylate, butyl acrylate and acrylonitrile
0 g (containing 25% of resin component) was added, and the mixture was slowly stirred at 1000 rpm or less so that the mixture became homogeneous.

This mixture was allowed to stand for a while, and thereafter, as shown in FIG. 4, it was applied on the first substrate 7 on which the drive electrodes 14 were formed by a bar coater to a film thickness of 30 μm, and then 60
It was dried at ℃ for about 1 hour. The film thickness after drying was about 10 μm. On the first liquid crystal layer 1 thus obtained, a protective film 41 having a film thickness of about 1 μm is formed by a spin coater, a bar coater or the like using epoxy, silicone or polymide resin, and further FSi (OC
₂ H _{5) 3} (LPCVD method of forming a film at room temperature using a fluorotriethoxysilane) (e.g. monthly Semiconductor W
orld 1992.4 p41), film thickness 100n
A SiO ₂ film 42 of about m was formed.

Subsequently, as shown in FIG. 5, an ITO film having a thickness of 200 nm was formed by a sputtering method and patterned by a usual photolithography and etching process to form a transparent counter electrode 17. The SiO ₂ film 42 is patterned into a desired shape by a normal photolithography and etching process, and then the SiO ₂ film 42 is used as a mask to perform oxygen ashing to pass through the protective film 41 and the liquid crystal layer 3 to the electrode pads 14a and 14b. A hole was formed.

Next, as shown in FIG. 6, a desired region on the SiO ₂ film 42 including the through holes is filled with, for example, Al.
A film is formed, and a NiSO ₄ solution is used to form N on the Al film.
Electroless plating method for forming i-film (eg 1989 SYMPOSI
The electrode pads 33a and 33b were formed by the method described in UM ON VLSI TECHNOLOGY 12-2). As a result, the electrode pads 33a and 33b are connected to the TFTs 5 and 6 via the electrode pads 14a and 14b, respectively.

Next, the counter electrode 17 and the electrode pad 33.
A chloroform solution of polymethylmethacrylate was applied onto a and 33b by a bar coater and dried at 100 ° C. for 2 minutes to form an insulating layer 8 having a film thickness of about 50 μm. Furthermore, sputtering method, LPCVD is performed on the insulating layer 8.
A SiO ₂ film 43 having a film thickness of 100 nm was formed by a method such as a method.

Then, as shown in FIG. 7, a film having a thickness of 200 nm is formed on the entire surface of the SiO ₂ film 43 by the sputtering method.
A film of ITO was formed, and the drive electrode 18 was formed by patterning by a normal photolithography and etching process. Subsequently, the SiO ₂ film 43 is patterned into a desired shape by a usual photolithography and etching process, and through holes reaching the electrode pads 33a and 33b are formed in the insulating layer 8 by oxygen ashing using the SiO ₂ film 43 as a mask. did. Then, electrode pads 35a and 35b were formed in desired regions on the transparent electrode 18 including the through holes by the electroless plating method as described above. As a result, the drive electrode 18 becomes the electrode pad 35.
It is connected to the TFT 5 via a, 33a and 14a.

As shown in FIG. 8, the second liquid crystal layer 2 containing magenta, for example, is formed by the same method as described above,
The protective film 44, the SiO ₂ film 45, the counter electrode 19, and the electrode pad 34b were formed. Further, the insulating layer 9, the SiO ₂ film 46, the drive electrode 20 and the electrode pad 36b were formed by the same method as described above. Thereby, the drive electrode 20 is
Electrode pads 36b, 34b, 35b, 33b and 14b
Will be connected to the TFT 6 via. After that, the third liquid crystal layer 3 containing cyan is formed by the same method as described above.

Separately from this, a black matrix 28 is formed as a substrate facing the first substrate 7 on a second substrate 10 similar to the first substrate 7, and is further planarized by using an epoxy resin. The film 26 is formed, and the planarization film 26 is further formed.
A transparent electrode 25 was formed on top. Then, the obtained second substrate 10 is bonded to the first substrate 7 on which the first, second and third liquid crystal layers 1, 2, 3 are formed, and the liquid crystal display device 47 shown in FIG. 1 is completed. In the liquid crystal display device 47, the TFTs 4, 5 and 6 are mounted in driver circuits, respectively, and the counter electrodes 17, 19 and 25 are connected by common wiring (not shown).
Connected to. Further, the light guide plate 22, the reflection film 23, and the backlight light source 21 are arranged on the side of the first substrate 7 opposite to the side on which the liquid crystal layer is formed.

In the liquid crystal display device thus obtained, the liquid crystal layers 1, 2, and 3 correspond to yellow, magenta, and cyan, respectively, and the liquid crystal layers 1, 2, and 3 are TFTs 4, 5, and respectively. Since it can be driven independently by 6, the full color display is possible. That is, the signal output from the TFT 6 reaches the drive electrode 20 via the electrode pads 14b, 33b, 35b, 34b and 36b, drives only the liquid crystal layer 3, and similarly the signal output from the TFT 5 is transmitted to the electrode pad 1.
Reach the drive electrode 18 via 4a, 33a and 35a,
Only the liquid crystal layer 2 is driven, and the signal from the TFT 4 directly reaches the drive electrode 14 to drive only the liquid crystal layer 1.

Since the GH liquid crystal is dispersed in the liquid crystal layers 1, 2 and 3 in a micro-encapsulated state, the liquid crystal layers 1, 2, and 3 are red and red, respectively, when no electric field is applied. The green and blue light components are absorbed, and when an electric field is applied, they become transparent. As a result, for example, by turning on only the TFT 6 and turning off the TFTs 4 and 5, only the liquid crystal layer 3 is in the transmissive state, and the liquid crystal layers 2 and 1 absorb the green and red light components, respectively. Only the blue component can be taken out and the blue color can be displayed. Embodiment 2 FIG. 9 shows one pixel of a reflection type liquid crystal display device of an active matrix drive using a subtractive color mixture method for color display in the present invention, and FIG. 10 shows vertical wiring of this device.

The liquid crystal display device 50 is constructed as follows. Similar to the first embodiment, in the first liquid crystal cell 71 in which the liquid crystal driving TFTs 4, 5, 6 are formed on the first substrate 7, the interlayer film 15 coated on the liquid crystal driving TFTs 4, 5, 6 is provided. And a drive electrode 57 formed on the anisotropic conductive film 56 and connected to the liquid crystal drive TFT 4. The drive electrode 57 has the function of a diffusive reflector and has irregularities on the surface opposite to the first substrate 7. An insulating film 58, a protective film 55, a first liquid crystal layer 59, and a counter electrode 60 are formed in this order on the liquid crystal drive electrode 57.

In the second liquid crystal cell 72, a liquid crystal driving T is provided on the counter electrode 60 via the SiO ₂ film 54 and the insulating layer 8.
A drive electrode 61 connected to the FT 5 is formed, and a protective film 53, a second liquid crystal layer 62, and a counter electrode 63 are formed in this order on the drive electrode 61. In the third liquid crystal cell 73, a drive electrode 64 connected to the liquid crystal drive TFT 6 via the SiO ₂ film 52 and the insulating layer 9 is formed on the counter electrode 63, and the drive electrode 64 is protected above the drive electrode 64. The film 51, the third liquid crystal layer 65, and the counter electrode 66 are formed in this order.

A transparent second substrate 10 is provided on the counter electrode 66 with a flattening film 26 and a black matrix 28 interposed therebetween. First, second and third liquid crystal layers 59, 6
Nos. 2 and 65 are constituted by dispersing a guest-host type liquid crystal microencapsulated in a polymer matrix in the same manner as in Example 1, and mixed with dichroic dyes of yellow, magenta and cyan, respectively. ing.

The vertical wiring will be described in more detail with reference to FIG. The liquid crystal driving TFTs 4, 5 and 6 formed on the first substrate 7 have bumps 67c and 67, respectively.
a and 67b are connected. The liquid crystal driving TFT 4 is
It is connected to the drive electrode 57 via the bump 67c.
The liquid crystal driving TFT 5 includes bumps 67a and electrode pads 68.
It is connected to the drive electrode 61 via a, 69a and 70a. Further, the liquid crystal driving TFT 6 has bumps 67.
The drive electrode 64 is connected via the electrode b, the electrode pads 68b, 69b, 70b and 80b.

The liquid crystal driving TFTs 4, 5 and 6 shown in FIGS. 9 and 10 have the same structure as that of the first embodiment. The liquid crystal display device 50 can be manufactured as follows. First, TFTs 4, 5 and 6 were manufactured as active elements on the same first substrate 7 as in Example 1. An interlayer film 15 is covered on these TFTs 4, 5 and 6, a contact hole is formed in this interlayer film 15, and an Al film having a thickness of about 1 μm is formed on the entire surface of the interlayer film 15 including the contact hole.
Alternatively, Au was formed into a film by a method such as a sputtering method or a vacuum evaporation method, and bumps 67c, 67a and 67b connected to the TFTs 4, 5 and 6 were formed by a photolinography and etching step or lift-off.

Next, in addition to the first substrate 7, FIG.
As shown in, the black matrix 28 is formed on the second substrate 10 similar to the first substrate 7 by a known method as in the first embodiment, and then a flattening film is formed thereon by using an epoxy resin. 26 was formed. Further, a 200 nm-thick ITO film was formed on the entire surface of the flattening film 26 by a sputtering method, and patterned into a desired shape to form a counter electrode 66.

Next, the third liquid crystal layer 65 is formed on the counter electrode 66. The liquid crystal layer in this example used a form in which GH liquid crystal was dispersed in a polymer. An ultraviolet curable resin is used as the polymer matrix, and the liquid crystal layer is separated into layers and dispersed as fine particles. At this time, the dichroic dye, which is not contained in the liquid crystal droplets and remains in the polymer matrix, is aligned during curing (Japanese Patent Laid-Open No. 05-002194) so that absorption does not occur during light transmission.

First, butyl acrylate and an acrylic oligomer (M-1200, manufactured by Toagosei Co., Ltd.) in a weight ratio of 3:
2 wt% for liquid crystal material (E8 made by BDH)
% P-type dichroic dye (any one of cyan, magenta, and yellow, for example, G232 made by Japan Photosensitive Dye Laboratory if yellow is added) is added, and a photocuring initiator (made by Merck Co., Ltd. is added. Add Darocur 1116) and stir well to disperse. This mixture was applied on the second substrate 10 on which the transparent electrode 66 was formed to a film thickness of 10 μm using a bar coater.

Next, the temperature is kept at 85 ° C. so that the liquid crystal molecules are not aligned, and an electric field of 300 kV / cm is applied for 30 minutes so that the liquid crystal material is in an isotropic phase. Orientation was performed. While maintaining this electric field, ultraviolet rays were irradiated for 2 minutes with an illuminance of 20 mW / cm ² using a high pressure mercury lamp to form a polymer dispersion type liquid crystal layer 65.

Further, a protective film 51 is formed on the liquid crystal layer 65 with an epoxy, silicone or polyimide resin, and then a film thickness of 20 is formed on the protective film 51 by a sputtering method.
A drive electrode 64 is formed by forming a 0 nm ITO film and patterning it by a normal photolithography and etching process.
Was formed. The insulating layer 9 having a thickness of about 50 μm was formed on the entire surface of the drive electrode 64 by the same method as in Example 1.

Then, as shown in FIG. 12, the insulating layer 9 is formed.
A film thickness of 10 is formed by a method such as sputtering or LPCVD
A 0 nm SiO ₂ film 52 was formed. This SiO ₂ film 5
The counter electrode 63 made of ITO was formed on the second electrode 2 in the same manner as in the first embodiment. Further, the SiO ₂ 52 was patterned, and the insulating layer 9 was etched using this as a mask to form a through hole reaching the drive electrode 64. Then, an electrode pad 81b was formed on a part of the SiO ₂ film 52 including the through hole by the same method as in Example 1.

Next, as shown in FIG. 13, the drive electrode 6
The second liquid crystal layer 62 containing magenta, for example, is formed on the electrode 3 and the electrode pad 81b by the same method as described above.
A protective film 53 was formed on the liquid crystal layer 62. Next, as shown in FIG. 14, the transparent electrode 61 was formed on the protective film 53 in the same manner as in Example 1. Then, a material having high oxygen plasma resistance such as photosensitive polysilane or disiranylene-π-electron polymer is used as a photoresist,
The liquid crystal layer 65 and the protective film 53 were etched by oxygen ashing to form a through hole reaching the electrode pad 81b. Electrode pads 80b were formed in the through holes by the same method as in Example 1. Next, the insulating layer 8 was formed by the same method as in Example 1.

Then, as shown in FIG.
A SiO ₂ film 54 was formed on the insulating film 54 in the same manner as in Example 1, and then a counter electrode 60 was formed on the insulating film 54. Furthermore, SiO
_{The 2} film 54 is patterned by the same method as in Example 1, and the insulating layer 8 is etched using this as a mask.
Through holes were formed to reach the electrode pad 80b and the drive electrode 61, respectively. Electrode pads 70b and 70a were formed in these through holes by the same method as in Example 1.

Next, as shown in FIG. 16, the first liquid crystal layer 59 was formed by the same method as the third and second liquid crystal layers 65 and 62. After that, a protective film 55 was formed on the first liquid crystal layer 59, and through holes were formed in the first liquid crystal layer 59 and the protective film 55. Then, electrode pads 69a and 69b were formed in the through holes, respectively. An insulating film 58 is formed of a transparent acrylic resin on the entire surface of the protective film 55 including the electrode pads 69a and 69b, and is patterned into a desired shape by a photolithography and etching process. Further, a concavo-convex structure was formed on the entire surface of the insulating film 58 by photolithography and etching steps. Insulating film 5
8 and electrode pads 69a and 69b, an Al film is formed on the entire surface by a sputtering method, and patterned by a normal photolithography and etching process.
The drive electrode 57 having the function of the scattering reflector is formed, and the conductive layer 6 is further formed on the electrode pads 69a and 69b.
8a and 68b were formed. The concavo-convex portion of the drive electrode 57 is arranged in an irregular pattern within one pixel so that the reflected light does not have wavelength characteristics due to diffraction or interference.

The second substrate 10 on which the third, second and first liquid crystal layers 65, 62 and 59 are formed in this way and the first substrate 7 having the active element formed in the previous step are shown in FIG. Positioning was performed so that the bumps 13 were at predetermined positions as shown in, and they were bonded using an anisotropic conductive film (56 in FIG. 9) to complete the liquid crystal display device 50 shown in FIG.

Also in this embodiment, as in the first embodiment, the liquid crystal layers 59, 62, and 65 are respectively composed of yellow, magenta, and
It corresponds to cyan, and each liquid crystal layer is connected to TFT4, 5, 6
Since they can be driven independently, full-color display is possible. Further, since GH liquid crystal is dispersed in each liquid crystal layer in the form of small liquid droplets, the liquid crystal layer 5 is in a state where no electric field is applied.
The light components of red, green, and blue are respectively absorbed at 9, 62, and 65, and the light scattered without being absorbed is also absorbed by the dichroic dye existing in the polymer matrix.
When an electric field is applied, the liquid crystal portion is in a transmissive state, and the dichroic dye in the polymer matrix is oriented so as not to be absorbed, so that the liquid crystal layer is in a transmissive state. As a result, for example, by turning on only the TFT 6 and turning off the TFTs 4 and 5, only the liquid crystal layer 65 is in the transmissive state,
In the liquid crystal layers 62 and 59, the green and red light components are absorbed, respectively, and only the blue component can be taken out, so that blue color can be displayed.

[0061]

According to the liquid crystal display device of the present invention, a plurality of liquid crystal driving active elements are formed on the first substrate, and three layers of liquid crystal cells are stacked on top of each other. In addition to being connected to the active elements for driving the liquid crystal on the first substrate, the three layers are formed by using the driving circuit in the active matrix system which is conventionally used for the color display by the subtractive color mixture method. The liquid crystal cells can be independently driven. Further, since no active element is formed in each liquid crystal cell, it is not necessary to form a thick insulating layer having strength such as a glass substrate. Moreover, since the polymer-dispersed liquid crystal is used for at least one of the liquid crystal layers, it is possible to separate the liquid crystal layers with a thin film instead of the substrate. Therefore, the thickness of the panel can be made sufficiently smaller than the size of the pixel, it is possible to prevent the occurrence of parallax when the display is obliquely observed, and to realize the above-described driving. There is no need to newly provide a special drive circuit, and an increase in manufacturing cost can be suppressed. Further, by using a liquid crystal composition containing different dyes in the liquid crystal layer in each liquid crystal cell, full-color display can be performed without using a conventionally used color filter.

Further, when the connection between each liquid crystal cell and the liquid crystal driving active element is made by a three-dimensional wiring penetrating each liquid crystal cell, the area of the wiring occupied in the pixel can be reduced, which is high. A liquid crystal display device having an aperture ratio can be obtained. Further, in the liquid crystal display device of the present invention, by using the liquid crystal driving electrode functioning as a reflection plate, as it is as a reflection type liquid crystal display device,
By using a transparent liquid crystal driving electrode and arranging a backlight below the first substrate, it becomes possible to use as a transmissive liquid crystal display device. Therefore, it is possible to improve the amount of light loss in the color filter, which is the biggest factor in reducing the light use efficiency, and to significantly reduce the power consumption of the backlight, and to reduce the power consumption of the new type of transmissive liquid crystal display device. It becomes possible to provide.

Further, according to the method of manufacturing a full-color liquid crystal display device of the present invention, since the liquid crystal driving active element is formed only on the first substrate, the liquid crystal driving active element is formed on the substrate of each liquid crystal cell. It is possible to omit the complicated manufacturing process. Further, as described above, since the liquid crystal driving active elements are arranged only on the first substrate, mounting circuits for driving these can be mounted on the same plane, which reduces the manufacturing process, A reduction in manufacturing cost can be realized.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part showing an embodiment of a liquid crystal display device of the present invention.

FIG. 2 is an enlarged schematic cross-sectional view of a main part for explaining vertical wiring of the liquid crystal display device of FIG.

FIG. 3 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

4 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

5 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

6 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

FIG. 7 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

8 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

FIG. 9 is a schematic cross-sectional view of a main part showing another embodiment of the liquid crystal display device of the present invention.

10 is an enlarged schematic cross-sectional view of a main part for explaining vertical wiring of the liquid crystal display device of FIG.

FIG. 11 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

12 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

13 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

14 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

15 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

16 is a schematic cross-sectional view of a main part for explaining a manufacturing process of the liquid crystal display device of FIG.

FIG. 17 is a schematic cross-sectional view showing an example of a liquid crystal display device using a subtractive color mixing method according to a conventional technique.

FIG. 18 is a schematic cross-sectional view showing another liquid crystal display device in the related art.

[Brief description of reference numerals]

1, 2, 3, 59, 62, 65 Liquid crystal layer 4, 5, 6 Active element 7, 10 Substrate 8, 9 Insulating layer 11, 71 First liquid crystal cell 12, 72 Second liquid crystal cell 13, 73 Third liquid crystal cell 14, 18, 20, 57, 61, 64 Drive electrode 15 Interlayer film 17, 19, 25, 60, 63, 66 Counter electrode 21 Backlight light source 22 Light guide plate 23 Reflective film 26 Flattening film 28 Black matrix 47, 50 Liquid crystal Display devices 14a, 14b, 33a, 33b, 34b, 35a, 3
5b, 36b, 68a, 68b, 69a, 69b, 70
a, 70b, 80b, 81b Electrode pad 56 Anisotropic conductive film 67a, 67b, 67c Bump 68a, 68b Conductive layer 42, 43, 45, 46, 52, 54 SiO ₂ film 41, 44, 51, 53, 55 Protection Film 58 insulating film

Claims (9)

[Claims] 1. A first substrate on which a plurality of liquid crystal driving active elements are formed, and first, second and third liquid crystal cells stacked in this order on the first substrate with an interlayer film interposed therebetween. A second substrate laminated on the third liquid crystal cell via a flattening film, wherein the first, second and third liquid crystal cells are a counter electrode and a liquid crystal layer formed for each liquid crystal cell. And a driving electrode connected to the liquid crystal driving active element on the first substrate, and electrically separated from the opposing electrode and the driving electrode of the adjacent liquid crystal cell by an insulating layer, respectively. A liquid crystal display device, wherein at least one of the liquid crystal layers constituting the second and third liquid crystal cells is formed of polymer dispersed liquid crystal. 2. The liquid crystal display device according to claim 1, wherein each liquid crystal layer contains a different dye. 3. The drive electrode of the second liquid crystal cell is formed by three-dimensional wiring penetrating the first liquid crystal cell, and the drive electrode of the third liquid crystal cell is formed by three-dimensional wiring penetrating the first and second liquid crystal cells.
The liquid crystal display device according to claim 1 or 2, wherein the liquid crystal display device is connected to each of the liquid crystal driving active elements. 4. The liquid crystal display device according to claim 1, wherein the drive electrode of the first liquid crystal cell is a reflective electrode. 5. The liquid crystal display device according to claim 1, wherein the drive electrode and the counter electrode are transparent electrodes, and a light guide plate is further provided on a surface of the first substrate opposite to the liquid crystal cell. 6. (i) A plurality of liquid crystal driving active elements are formed on a first substrate, an interlayer film is formed on the entire surface of the liquid crystal driving active elements, and (ii) a second interlayer insulating film is formed on the interlayer film. A drive electrode connected to the first liquid crystal drive active element, a liquid crystal layer, and a counter electrode are laminated in this order to form a first liquid crystal cell, and (iii) an insulating layer is provided on the first liquid crystal cell. A drive electrode connected to the second liquid crystal drive active element, a liquid crystal layer, and a counter electrode in this order to form a second liquid crystal cell, and (iv) insulation on the second liquid crystal cell. A drive electrode connected to a third liquid crystal drive active element via a layer, a liquid crystal layer, and a counter electrode are laminated in this order to form a third liquid crystal cell, and a flat surface is formed on the third liquid crystal cell. The method for manufacturing a liquid crystal display device according to claim 1, wherein the second substrate is laminated with a chemical film interposed therebetween. 7. (I) Forming a plurality of liquid crystal driving active elements on a first substrate, forming an interlayer film on the entire surface of the liquid crystal driving active elements, and (II) planarizing on a second substrate. A counter electrode, a liquid crystal layer and a drive electrode are laminated in this order via a film to form a third liquid crystal cell, and (III) a counter electrode, a liquid crystal layer and a drive electrode on the third liquid crystal cell via an insulating layer. Are laminated in this order to form a second liquid crystal cell, and (IV) a counter electrode, a liquid crystal layer, and a drive electrode are laminated in this order on the second liquid crystal cell to form a first liquid crystal cell. 2. The liquid crystal display device according to claim 1, wherein the first substrate and the second substrate obtained by (V) are bonded so that each active element for driving liquid crystal and the drive electrode are connected. Production method. 8. The method of manufacturing a liquid crystal display device according to claim 6, wherein the drive electrode of the first liquid crystal cell is formed of a reflective conductive material. 9. The method for manufacturing a liquid crystal display device according to claim 6, wherein the drive electrode and the counter electrode are formed of a transparent conductive material, and a light guide plate is further formed on the surface of the first substrate opposite to the liquid crystal cell. .